Introduction

This page describes patient's use cases, in a personal health environment (PHE) context, in relation to the information standard Medication Process (MP). These use cases are based on version 9.x of this standard. Functional specification of these use cases are described at the functional design wiki page. The technical specification is described here. HL7 FHIR STU3 is used for this purpose.

The Medication Process information building blocks are adopted by 'Registratie aan de Bron' and converted to Health and Care Information models, also called ZIB's. In order to exchange medication information between systems, FHIR representations of these ZIB's are made and used in the transactions described on this page.

Use case: retrieve medication overview

This FHIR implementation guide assumes that the PHR system is able to make a connection to the right XIS that contains the patient's information. It does not provide information on finding the right XIS nor does it provide information about security. Moreover, each transaction is performed in the context of a specific authenticated patient, for whose context (token) has been established using the authentication mechanisms described in the 'Afsprakenstelsel'. Each XIS Gateway is required to perform filtering based on the patient associated with the context for the request, so only the records associated with the authenticated patient are returned. For this reason, search parameters should not be included for patient identification.

Introduction

The retrieve medication overview transaction is used by the PHR to retrieve a medication overview from the XIS.

Actors

Transaction group

Transaction

Actor

Role

Retrieve Medication Overview(PULL)

Retrieve medication overview request

Patient (using a PHR)

Request medication overview from the XIS

Retrieve medication overview response

Healthcare professional (using a XIS)

Serves medication overview to the PHR

Invocations

PHR: request message

This message uses an extended operation on the RESTful API to obtain a medication overview from a XIS. This operation is used because the XIS needs to play an active role in formulating the content of the response.

Trigger Events

When the patient(PHR) wants to obtain the current medication overview, it issues a retrieve medication overview request message.

Message Semantics

The PHR executes a medication-overview operation with HTTP POST against the XIS's base endpoint as shown below.

POST [base]/$medication-overview

Expected Actions

The XIS shall process the operation to find or generate and return the current medication overview.

XIS: response message

The XIS returns a HTTP Status code appropriate to the processing of the operation as well as a Bundle of type 'collection', containing one List and one Patient resource along with other resources that represent the Medication Overview.

Trigger Events

Message Semantics

Based on the medication-overview operation processing results, the XIS will either return an error or success. When the XIS needs to report an error, it shall use HTTP error response codes and shall include a FHIR OperationOutcome resource with more details on the failure. If the request message is processed successfully, whether or not a Medication Overview is found or generated, the HTTP status code shall be 200.

The body of the response message shall be a Bundle resource of type "collection". The following section will elaborate on the content included.

If the XIS is sending warnings, the Bundle resource shall also contain a FHIR OperationOutcome resource that contains those warnings. The FHIR specification describes the relevant sections:

Message content

The outcome of the medication-overview operation is the body of the medication overview request message. Successful processing of this operation should result in a Bundle recourse, containing one List and one Patient resource as entries along with all the resources that represent the current medication overview. These resources SHALL be referenced from the List resource. The clinical content of the medication overview is defined in the Medication Process specification. The functional dataset of the medication overview can be found on decor.nictiz.nl.

The content in the response message SHALL be a valid instance of the following profiles. Clicking on the link will open the formal definition on Simplifier.net.

The Bundle profile represents the structure of the retrieve medication overview response message. The List profile represents the actual medication overview. The List contains the medication overview metadata and references to all resources that constitute the medication overview. These resources are included in the Bundle as entries. The returned Bundle has at least one List and one Patient resource.

All returned resources to the PHR, including the Bundle and List, SHALL include their related profile canonical URL in the meta.profile element in order to show compliance. The resources in the response message SHALL be a valid instance of these profiles. In the table below, the ZIB's that constitute the clinical content of the Medication Overview and their respective profiles are listed.

Note that the medication building blocks are grouped per 'medication treatment' conform the Medication Process specification. Grouping SHALL be done by use of a 'medication treatment' identifier. This identifier shall be the same across different related medication resources that constitute a medication treatment. The zib-Medication-MedicationTreatment extenstion is added to all medication profiles and can be used for this grouping purpose.

Search parameters

Use case: retrieve medication information

This FHIR implementation guide assumes that the PHR system is able to make a connection to the right XIS that contains the patient's information. It does not provide information on finding the right XIS nor does it provide information about security. Moreover, each transaction is performed in the context of a specific authenticated patient, for whose context (token) has been established using the authentication mechanisms described in the 'Afsprakenstelsel'. Each XIS Gateway is required to perform filtering based on the patient associated with the context for the request, so only the records associated with the authenticated patient are returned. For this reason, search parameters should not be included for patient identification.

Introduction

The Retrieve Medication Information transaction is used by the PHR to retrieve medication information from the XIS. The PHR can use this transaction to retrieve the wanted information by searching on specific medication building blocks.

Actors

Transaction group

Transaction

Actor

Role

Retrieve Medication Information(PULL)

Retrieve medication information request

Patient (using a PHR)

Request medication information from the XIS

Retrieve medication information response

Healthcare professional (using a XIS)

Serves medication information to the PHR

Invocations

PHR: request message

This message uses the HTTP GET method parameterized query to obtain medication information from a XIS. Multiple different HTTP GET request messages may be needed to retrieve all medication information.

Trigger Events

When the patient(PHR) wants to obtain medication information matching various parameters, it issues a retrieve medication information request message.

Message Semantics

The PHR executes an HTTP GET against the XIS's medication FHIR endpoints. These endpoints can be one of the following:

This URL is configurable by the PHR by configuring the query search parameters and search control parameters to modify the behavior of the XIS such as response format, or pagination. An example of a search for MedicationRequest resources:

GET https://vonk.test-nictiz.nl/MedicationRequest?date=gt2010-10-01

This search interaction will finds any MedicationRequest resources changed since 1-Oct 2010.

Including other resources in searchresults

The PHR may request that the XIS return resources related to the search results, in order to reduce the overall network delay of repeated retrievals of related resources. This is useful when the PHR is searching on a clinical resource, but for every such resource returned, the client will also need the subject (Patient resource) or prescriber (Practitioner resource) or medication that the clinical resource refers to. The client can use the _include parameter to indicate that the subject resources be included in the results. Example search:

GET [base]/MedicationRequest?&category=http://snomed.info/sct|16076005&_include:MedicationRequest:medication

This search interaction will find all MedicationRequest resources of the category MedicationAgreement and if present include the referenced Medication resource.

Query Search Parameters

The PHR may supply, and the XIS SHALL be capable of processing, all query parameters listed in the table below. The XIS may choose to support additional query parameters beyond the subset listed below. Any additional query parameters supported shall be supported according to the core FHIR specification. Such additional parameters are considered out of scope for this transaction.

Search on medication use in the past, present or future within the specified time period.

periodofuse **

MedicationDispense, MedicationRequest

DispensePeriod

Returns all medication dispenses within the specific period.

whenhandedover

MedicationDispense

* The FHIR profiles that represent the medication building blocks contain fixed code values in the .category elements to allow searching on specific medication building blocks. FHIR resources MedicationAdministration and MedicationDispense do not contain a 'category' search parameter in the FHIR specification. Custom search parameters are provided.

** The search parameter consists of a custom created FHIR search parameter not represented in the FHIR specification.

Custom Search Parameters

Search on fixed category code

To distinguish the ZIB medication building blocks between general medication resources, a fixed category coding has been added to the ZIB medication profiles. This fixed category code is solely used for indexing and retrieval of the ZIB building blocks. These category codings be found in the in the profiles at the .category element. The profiles are listed at the response message section below.

Trigger Events

Message Semantics

Based on the query results, the XIS will either return an error or success. When the XIS needs to report an error, it SHALL use HTTP error response codes and SHOULD include a FHIR OperationOutcome resource with more details on the failure. If the request message is processed successfully, whether or not any medication resources are found, the HTTP status code SHALL be 200.

The response message SHALL be a Bundle resource of type "searchset" containing zero or more FHIR resources as entries. If the XIS is sending warnings, the Bundle resource SHALL also contain a FHIR OperationOutcome resource that contains those warnings. The FHIR specification describes the relevant sections:

Message resource content

The returned data to the PHR should conform to the medication ZIBs profiles. In the table below the medication ZIB's and their respective FHIR profiles are listed. The resources in the response message SHALL be a valid instance of these profiles. All resources SHALL include their related profile canonical URL in the meta.profile element in order to show compliance.

Note that the medication building blocks are grouped per 'medication treatment' conform the Medication Process specification. Grouping SHALL be done by use of a 'medication treatment' identifier. This identifier shall be the same across different related medication resources that constitute a medication treatment. The zib-Medication-MedicationTreatment extenstion is added to all medication profiles and can be used for this grouping purpose.